gauges questions

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Oct 15, 2002
as some may know, i have a 71 fj40 with a chevy 327. i'm trying to make the original gauges work.

1) what is the alternator gauge supposed to be hooked up to?
2) the temperature gauge has two wires, but the temperature sensor on the 327 has ablack tube coming off of it, how can i make this work?
3) same question for the oil pressure gauge, two wires but the 327 uses a tube with oil in it.

any help or suggestions would be appreciated.
alternator (ammeter) gauge black/red wire goes to ignition switch black/red wire-hooks up with your alternator and fuse box other wire white goes directly to your battery with a fusible link make sure not to ground either of these wires

should be only one wire coming off the temp gauge and oil guage temp is yellow green and oil is yellow/black theres two wires coming off the back of mine, but the one, believe its yellow connects all the guages not sure what that does (ground?) if you have your old connection plugs should be able to just plug in, not sure about using with the 327 though
The ammeter must run all of the amperage through it. I would not use one as it is a much simpler and safer method to run your alternator output directly to the battery. If you have a short or open in that wire going all the way up to the dash and back out to the battery, you will have no power at best and a major fire at worst. Run a voltmeter.

The oil pressure sending unit and coolant temp sending units are not the same. you can get adapters to the stock sending units from the usual cruiser parts sources. You already have mecahnical sending units on your motor from the PO. It would be way simpler to just use those.
If you dont run an amp meater were do you hook up power to the fuse block? and how do you hook up a volt meater?
i saw an fj40 on ebay where a guy put aftermarket gauges in the original instrument cluster. has anyone done this, or does anyone have info on what gauges were used, and how to do it?
Man-a-fre has a replacement guage panel available to replace factory guages in stock location. I just intalled one and it looks great. Plan on spending $400-$600 on this if you want quality guages. You will also have to fabricate a sending unit for the gas tank as no one to my knowledge makes a aftermarket guage compatible with the stock sending unit. The guage panels are not on MAF's web site, part #'s 40dashpanel1 (1, 3-3/8" and 4, 2-1/16" guages) or 40dashpanel2 (2, 3-3/8" and 3, 2-1/16" Guages) I think they run about $45 for the panel. BTB also has a aftermarket set up that is pretty cool but a lot of money.

If you keep your factory guages you will need to get adapters to use the stock toyota sending units on your chevy small block if you want the guages to read properly. (water temp. and oil pres.) If you use chevy sending units with your toyota guages they will always read low but will work. You will just need to get used to where the "normal" readings will be for your engine. But as your current sending units have tubes coming out of them, they are intended for mechanical guages. So they will not work with your stock ones anyway. I'd get the adaptors or go with the new guage idea. Which ever fits your budget.
I converted all my gauges over to aftermarket ones some time ago. I have a panel very much like the MAF one, but got from a different source. I have speedo, tach, water temp, oil pressure and fuel on the dash. I have amp and volt meters mounted at eye level on my roll cage. My water temp and oil pressure gauges are mechanical.

I couldn't be happier with the setup, and would do it all over again if needed. Good gauges are not really cheap, but in the long run they are worth every penny.
so does the voltmeter hook up to the alternator and a ground?
I hooked my voltmeter up to the ACC side of the fuse block I put in. That way I have a volt meter reading if I am using things like the radio running and the engine stopped.

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